Hitch box extension



FIG. 1 is a top view thereof;

FIG. 2 is an enlarged right side elevational view thereof;

FIG. 3 is a greatly enlarged rear view thereof;

FIG. 4 is an enlarged left side elevational view thereof;

FIG. 5 is a greatly enlarged front view thereof; and,

FIG. 6 is a bottom view thereof. 

The ornamental design for a hitch box extension, as shown. 